Various pumps have been utilized over the years to circulate paint and similar materials through a system. While air-operated reciprocating piston pumps have long been popular for this use, there has been an increased desire to migrate to more efficient electric powered solutions. Electric powered centrifugal pumps, progressive cavity pumps and screw drive reciprocating piston pumps (U.S. Pat. No. 5,725,358) have all been commercialized. Whichever technology is utilized, it is desired to minimize pulsation so that a constant system pressure is present. Multiple reciprocating piston pump systems (Graco Inc.'s GM10000 airless sprayer, published PCT application WO 02/46612 A1 and U.S. Pat. No. 5,145,339) have been made wherein the pumps are offset in phase so as to minimize pulsation.